Orthotopic liver transplantation is an effective and increasingly popular therapy for a variety of liver diseases but there is as yet no method for temporarily sustaining a patient awaiting transplant who enters into hepatic failure. C3A is a human liver cell line derived from an hepatoblastoma that retains most of the characteristics of the human hepatocyte. We have cultured these cells in hollow fiber devices and shown that they are capable of carrying out many of the major liver-specific metabolic interconversions. We have successfully tested this device in an animal model of fulminant hepatic failure and in four human subjects. In preparation for a multisite trial of this device, we propose to undertake a feasibility study of five patients gathered from the affiliated hospitals of the Baylor College of Medicine and at the Hermann Hospital, Univ. of Texas School of Medicine. The use of liver transplantation is limited by both the availability of organs and financial constraints. An ELAD should have application in a number of transplant situations. First, it will allow patients in fulminant hepatic failure to be stabilized and calmly evaluated before operating. Second, it will find use in stabilizing and assisting patients after transplant, particularly in situations in which the graft fails on reperfusion. Third, in some instances it may serve as a substitute for transplant. This device would allow time for the patient's natural liver to regenerate, sparing the expense of operation, the lifelong dependence on immunosuppression and the likelihood of premature mortality.